1. Field of the Invention
This invention relates to a process for producing an acicular iron .alpha.-oxyhydroxide used as a starting raw material for acicular iron oxide and metal iron powder for magnetic recording.
2. Description of the Related Art
As to recent magnetic recording, a further higher level of magnetic characteristics and dispersibility has come to be required for magnetic powder for magnetic recording, with its higher performance and more compactness. In order to satisfy such requirements, it is necessary to improve the characteristics of iron .alpha.-oxyhydroxide particle powder, i.e. its dispersibility, particle shape and particle size distribution.
Conventional iron .alpha.-oxyhydroxide is unsatisfactory in the aspect of the dispersibility of each particle, i.e., preparation of single particle, dendritic particles are observed and a large amount of fine particles is present in a product so that its particle size distribution has been broad. Thus, since the magnetic tape prepared using such magnetic powder particles is inferior in its dispersibility in magnetic paints and has dendritic particles in admixture, it is inferior in the degree of orientation, low in the remanent induction and broad in the particle size distribution so that its erasion transfer characteristics have been inferior.